Implementation of a perineal support programme for reduction of the incidence of obstetric anal sphincter injuries and the effect of non-compliance.

OBJECTIVE

Obstetric anal sphincter injury (OASI) is a serious complication of a vaginal delivery. In 2005, a Norwegian nation-wide training programme to reduce the OASI rate was successfully implemented. The aim of the present study was to assess the impact of a perineal support programme, inspired by the Norwegian programme, on the incidence of OASIs in a Dutch hospital with a low a priori rate.

STUDY DESIGN

Prospective cohort study with historical comparison group. Three midwives and one obstetrician were trained on site by an expert midwife from Norway. These four trained the rest of the obstetrical staff. Data were prospectively recorded using the Dutch National Perinatal Registry, with additional recording whether the manual perineal support was actually applied in individual deliveries. OASI rates in three time periods were studied: the year preceding the training programme, the training period of 7 months and the year after the training period (respectively "control period", "training period" and "result period"). After exclusion of caesarean sections, preterm deliveries, breech and twin deliveries, a total of 4391 deliveries were recorded during the study period.

RESULTS

During the training period, the OASI rate decreased significantly from 2.0 to 0.7% (aOR 0.34; 95%CI 0.15-0.76). In the result period, manual perineal support was performed in 72.7% of the deliveries and the overall OASI rate raised to 1.7% again, mainly because of non-compliance to the programme during vacuum deliveries. Nevertheless, multivariate logistic regression analysis with correction for known OASI risk factors showed that the OASI rate was 83% lower with application of perineal support (aOR 0.17; 95%CI 0.07-0.39).

CONCLUSION

A perineal support programme decreases OASI rate. Continuous verification of application and repetitive training is necessary, especially during vacuum deliveries.